Extrusion press



June 4, 1929. J. P. MADDEN 1,715,936

EXTRUSION PRESS Filed Aug. 25, 1925 1' A BY ATTORNEYS Patented June 4, "1929.

UNITED STATES PATENT OFFICE.

JAMES P. MADDEN, F BETHLEHEM, PENNSYLVANIA, ASSIGNOR TO BETHLEHEM STEEL COMPANY.

EXTRUSION PRESS.

Application filed August 25, 1925. Serial No. 52,259.

The present invention relates to cylinders for extrusion presses. In carrying out the extrusion process in connection with metals, the metals are first heated so as to become plastic and are then placed, while in this condition, in the cylinder of a press. An extruding die, having an aperture of the shape to be produced. is held in the press in juxtaposition with the end of the cylinder; the

aperture being preferably coaxial with the bore of the cylinder. The metals to be extruded are subjected to great pressure by means of a plunger so that the metal issues in a bar having the same cross section as that of the opening or aperture in the die, through which it is forced. Certain metals are extruded in this manner with little difiiculty event at relatively low temperatures while other metals, particularly those of the cuprum group, oifer great resistance and must be highly heated to reach a state of the desired plasticity.

The metal of the cylinder, which is usually of forged steel, is affected by the heat impart- 5 ed thereto by the metal flowing therethrough at high temperatures, and deteriorates rapidly and eventually affects the physical characteristic of the metal forming the cylinder.

The constant replacement of the cylinder may so increase the cost of production by this process that it cannot be commercially practiced with certain metals.

The object of the present invention is to provide a cylinder having means whereby it may be maintained in a relatively cool state, notwithstanding the hot metal passing therethrough, that. is, having means to prevent the heating thereof to such an extent that the physical properties of the material forming the cylinder are adversely affected.

This object is accomplished by constructing the cylinder with one or more condults or chambers for a cooling fluid and in constantly paming cooling I fluid through the cylinder when the extrusion process 18 being .carried out.

It is often desirable to preheat the cylinder before commencing an extrusion operation and this may conveniently be accomplished in a cylinder constructed in accordance with the present invention, by circulating steam or other heated fluid through the conduits or chambers provided for the passage of the cooling fluids before the commencement of the extrusion operations.

The novel feature will be more i' Lilly understood from the following description and claims taken with the drawings:

In the drawings:

Fig. 1 is a longitudinal section through a cylinder embodying the invention and illustrating the die in position;

Figs. 2, 3 and 4 are longitudinal sections through the disassembled members of the cylinder.

Referring to the drawings, 10 indicates generally the cylinder supported on the bed 11 of an extrusion press. Straps 12 are provided to hold the cylinder in place. A die 13 is positioned at the end of the cylinder and coaxially with the bore thereof. 14 is a plunger adapted to slidably fit the bore of the cylinder and is operated, to extrude the metal placed in the cylinder through the die aperture. The cylinder is built up of a plurality pf tubular members and is constructed as folows.

A tubular container member is indicated at 15, the exterior of which is provided with oppositely facing annular shoulders 16 toenable it to be conveniently secured in the bed 11 and the cylindrical inner wall of which is provided with two spiral grooves 17 and 18, respectively, each groove extending from' a point adjacent the end of the cylinder to approximately the center thereof. The grooves are discontinued before intersecting, leaving a fin or portion of the cylinder wall 19 between their inner ends and do not emerge at the ends of the cylinder, leaving end fins or portions 20. The outer ends of the grooves are connected respectively, by fluid conduits 21 with the respective ends of the cylinder and these fluid conduits are threaded at their outer terminals to receive the corresponding thread ends of fluid supply pipes, which are not illus'tlirated. Leading radially outward from the inner ends of the grooves are fluid conduits 22 which terminate at the cylindri cal exterior wall of the container. the outer ends of these conduits being threaded, at 23. to receive the threaded ends of the fluid conducting pipes. the inner ends of the grooves may be brought into communication with openings in the ends of the container 15, as by means of conduits 24, plugs being secured in the outer ends of the conduits 21 to prevent the escape of fluid.

An annular seat 25 at the bottom of a recess concentric with the axis of the cylindri- If found more convenient,

cal inner wall of the container, constitutes a seat for the annular flange 26 of a bushing 27 which lies Within the container.

Intermediate the container and the bushing is a sleeve 28 having cylindrical outer and inner walls which fit closely against the inner wall of the container and the outer wall of the bushing, respectively. The sleeve constitutes a closure for the grooves 17 and 19 so that fluid introduced, for instance, through conduits 21 will flow in a helical path through the grooves and finally escapes through outlet conduits 22. In order that the sleeve 28 shall constitute a fluid-tight closure for the grooves 17 and 18, it is preferably positioned by a shrinkage operation, the container being formed with its inner diameter slightly smaller than the outer diameter .of the sleeve and being placed over the sleeve while in a heated and expanded condition and shrunk thereon.

It should be-understood that the sealing of the grooves may be effected by assembling the bushing 27 directly in contact with the inner surface of the container and thus eliminate the intermediary sleeve. However, in the present construction,'said sleeve is adapted to provide a smooth surface in contact with the exterior surface of the bushing to facilitate replacement of the latter when necessary.

When it is desired to heat the cylinder as a step preliminary to anextruding operation, steam or other heated fluid may be passed through the grooves and its heat imparted to the cylinder. I/Vhil the extrusion process is being carried out, cooling water may be circulated through the grooves and inasmuch as this water is close to the bushing it will keep the bushing at a satisfactory temperature. Two grooves instead of a single groove are used in' order that the water will not have so great a distance to travel that it will be vaporized by the heat. Instead of two grooves, three or more grooves may be provided in order that a greater cooling effect may be realized, and it will be obvious that minor details of arrangement and design of the com ponent parts of the invention may be made without departure from its spirit or scope.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a press for extruding metals, the combination with a bed, of a cylinder adapted to receive the metal to be extruded, a (lie member fixed in juxtaposition'with the end of said cylinder, a plunger adapted to operate in said cylinder and extrude the metal through the die member, said cylinder comprising a bushing, a sleeve surrounding the bushing a supporting member surrounding said bushing and sleeve, and a chamber intermediate the sleeve and the bushing through which heating or cooling fluid may be circulated circumferentially about the bushing.

2. In a press for extruding metals, a cylinder comprising an outer tubular member having a plurality of non-intersecting spiral grooves formed in the interior surface, said grooves extending from a point adjacent the ends of saidmember to approximately the center thereof providing a relatively thin wall to prevent communication between the grooves, conduits leading from the terminal portions of said groove to the exterior of said tubular member, a sleeve fitting within said tubular member to constitute the grooves a fluid-tight chamber, and a bushing fitting within said sleeve.

In testimony whereof I hereunto aflix my signature this 5th day of August, 1925.

JAMES P. MAD'bEN. 

